近海激光通信分集技术对大气湍流扰动抑制的实验

为评估分集收发技术在近海面激光通信系统应用中对大气湍流扰动的抑制作用,设计了基于对多路1 550 nm激光光斑同步采集的验证实验方案。采用由时统终端触发的FPGA+多核DSP架构的实时图像处理系统实现目标中心位置的提取与目标灰度和的统计,进而得到激光从发射端至接收端的到达角起伏方差和闪烁指数。分别比较了等功率条件下单路发射和双路发射间、双孔径接收与等效单孔径接收间的到达角起伏方差和闪烁指数,同时比较了不同跨距下双孔径接收的效果。实验表明,在发射功率相同的情况下,与单路发射相比,双路发射能够有效地抑制因大气湍流扰动产生的到达角起伏和光强闪烁;在接收面积相同情况下,双孔径接收较单孔径接收所产生的到达角起伏与光强闪烁更弱,且在一定范围内,双孔径间的跨距存在最优值。

Experiment of restraint of atmospheric turbulence using diversity technology based on analysis of offshore laser communication

To evaluate inhibitory effect of diversity transceiver technology on the atmospheric turbulence in the application of offshore laser communication system, experiment verification scheme of multi-channel synchronous acquisition of laser spot based on 1 550 nm was designed. Extraction of target center position and target gray statistical of real time image processing system were realized by using terminal triggered with the FPGA+ multi-core DSP architecture, and then the arrival angle fluctuation variance and the scintillation index from the laser transmitting terminal to the receiving terminal were obtained. Under the conditions of equal power, arrival angle fluctuation variance and the scintillation index were compared between single way transmitting and double way transmitting, double aperture receiving and equivalent single aperture, and the effect of double aperture receiving was compared under different spans. Experimental results show that the same transmitting power, the arrival angle fluctuation variance and the scintillation index are effectively inhibited caused by atmospheric turbulence with dual way transmitting compared with single way transmitting; in condition of same reception area, the arrival angle fluctuation variance and scintillation index is more weak through single aperture receiving compared with double aperture receiving. In a certain range, double size span exists optimal values.